I am a new fish owner who just got my first betta last week. At first, he seemed perfectly healthy. He was very active, bright red, and had a huge appetite. But two days ago, he became very lethargic, his color turned dull and grayish, and his fins are always clamped down against his back. He doesn't eat very much anymore, and he hangs around the top of his tank all day in a corner. I'm thinking this happened because the tempature in the room he was in fluctuates often, sometimes reaching 64 at night(it gets VERY cold in the winter where I live). The tank had a heater, so I thought it would be ok - I won't be making that mistake again!We moved him to a different room this morning that will hopefully stay warmer. Is there anything else I can do to help him recover? Do you think that it is possible for him to recover? He looks absolutely terrible- I feel so bad for him.

Housing
What size is your tank? 1.5 gallons.
What temperature is your tank? It was fluctuating between 67 and 72, but hopefully it will be more consistent now.
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? No
Is your tank heated? Yes
What tank mates does your betta fish live with? None

Food
What type of food do you feed your betta fish? Pellets
How often do you feed your betta fish? Twice a day, usually 2-3 pellets each time.
Maintenance
How often do you perform a water change? We just got him last week, so we have only changed his water 50% once so far.
What type of additives do you add to the water when you perform a water change? Betta Complete Water Conditioner.

Symptoms and Treatment
How has your betta fish's appearance changed? Yes, his fins are clamped down and his coloring is pale and grayish.
How has your betta fish's behavior changed? Yes, he is lethargic and hangs around in the top corner of the tank all day.
When did you start noticing the symptoms? Two days ago.
Have you started treating your fish? If so, how? We were given "Betta Fix" when we talked to someone at the fish store.
Does your fish have any history of being ill? We just got him last week, and he seemed very healthy.
How old is your fish (approximately)? I don't know.

He's still freezing at 72. Bettas need temps between 76-82 with 78-80 being ideal. Also huge swings are really hard on them. You also need to be using an in tank thermometer because the tank water will be colder than the room temp and you can't rely on the heater without checking.

He needs to be warmed up.. slowly to avoid shock.

In a tank of this size you need two water changes a week - one 50% and one 100% including a thorough rinsing of gravel and all decor.

Really, 2 gallons is minimum for a betta healthy long term, and if you get that size you can get a good adjustable 25w heater that can keep his tank a stable temp up to 15 degrees above room temp. If you keep your house that cold you absolutely need it. I like Jager and Marineland Visitherm, personally. You need the same water change routine for anything under 5g.

This is how you do a large water change without shocking:

Quote:

To do a water change, use a little cup like a plastic solo cup - this cup must be only for him and have never been used with soap or other chems. Scoop him up in this cup (keep him in the cup about 1/4 full of water - it doesn't need to be much because he won't be in it for long) and leave him in the cup while you change his water. To do the 50% use a turkey baster - dedicated only to him that has never seen soap or chems - and drag it through the gravel and try to suck as much of the poop out as possible, in addition to 50% of the water. Use a thermometer under the running tap to get it to be the same temp as the water that is normally in his tank. When the thermometer says the flowing tap is the right temp, fill back up his tank. At this point, add the conditioner (dose for how much water you change - if you change half the water you add half gallon worth of conditioner, If you do a 100% water change dose for the full gallon change). Float his plastic cup with him in it in the new water. Slowly add a couple tablespoons of the new water into his cup every 10 minutes for at least an hour. Finally, dump him in gently but try to get as little of the old cup water back into the tank as possible. When you do the weekly 100% you will do mostly the same thing except empty his tank fully and rinse everything in it very well under warm water but never use soaps or chemicals. Once it's fully cleaned/rinsed you can refill it and repeat the cup/acclimate phase.